In the related art, in order to acquire information about components contained in a specimen, specific types of light coming from individual positions of the specimen are detected, optical spectra, such as Raman spectra, infrared absorption spectra, or the like, are acquired by diffracting the detected light, and the acquired optical spectra are analyzed (for example, see Patent Literature 1 and Non-Patent Literature 1).
In the case in which the light coming from the specimen is weak, it takes time to measure the optical spectrum once, and thus, it takes longer to acquire sufficient numbers of optical spectra. In Patent Literature 1 and Non-Patent Literature 1, the overall measurement time is reduced by simultaneously acquiring optical spectra at a plurality of positions by using line-shaped illumination light or by synchronizing the charge read-out of a detector that detects light coming from the specimen and scanning of the illumination light.